1. Field of the Invention
The present invention relates to a printed circuit board which can be formed three-dimensionally.
2. Related Background Art
Since a printed circuit board comprises a thin plate, it may be bent when a depression switch mounted thereon is actuated, so that secure on-off operation cannot be assured. Also such board bending may lead to damage to the electronic component mounted on the circuit board, by eventual contact with other components, detachment of terminals of such electronic component, or breakage of the wirings formed on the circuit board. Breakage of the circuit board itself may occur.
For this reason, the board bending has conventionally been reduced by the reinforcement of the board itself, for example by change of the board material or increase in the board thickness. Also attempts have been made to reduce the board bending by increasing the supporting positions of the board or the supporting area thereof.
However, the change in the material or thickness of the circuit board itself is not too effective if the size of the circuit board is large, and may lead to an increase in the weight and cost of the board.
Also, the increase in the number of supporting positions of the board or in the supporting area thereof is encountered by the following difficulties.
In the equipment employing the printed circuit board, the supporting parts may not necessarily be provided at desired positions because of spatial limitation.
Also, the board designing becomes difficult, in order to provide the supporting parts in suitable positions.
Furthermore, the increased number of supporting parts on the printed circuit board is against space saving, and is disadvantageous for component mounting, since such electronic components or wirings cannot be placed on such supporting parts.